I got a Nokia 770 recently - fun thing to play with. I've stuck some of the stuff I've been working on in svn.
I managed to get a semi-working scratchbox and to compile some stuff I was missing and couldn't find. The one I really wanted was diff, and I managed to get that compiled, so theres cmp, diff, diff3, and sdiff. Also threw in cal.
I also managed to get nvi compiled. The busybox vi is pretty terrible, and vim seems kind of overkill for a 770 plus the port to 770 advertises itself as fairly tricky and incomplete. I haven't noticed any issues with this binary so far.
Also a little lan manager script (lan) that can show internal and external IP and wlan name. You need curl and wireless-tools for that.
Finally, my famous command line twitter client tweaked to use /bin/sh :)